Insulating material.



UNITED STATES PA TENT OFFICE.

JOSEPH L. R. HAYDEN, 0F SCHENECTADY, NEW YORK, ASSIGNOR T0 GENERALELEGTRIC COMPANY, A CORPORATION OF NEW YORK.

INSULATING MATERIAL.

No Drawing.

To all whom itimqg conccrn Be it known that I, J OSEPH L. R. HAYDEN, acitizen of the United States, residing at Schenectady, county ofSchenectady, State of New York, have invented certain new and usefulImprovements in Insulating Material, of which the following is aspecification. This invention relates to electric insulating materialand has for its object the provision of material of this character whichwill be highly insulating and at the same time very easily and cheaplyproduced.

One of the objects of my invention is to produce an insulating materialwhich will have'its disruptive strength raised upon rise of temperature.It has been found that all the drying animal and vegetable oils have thesame effect of enormously decreasing disruptive strength at a moderateincrease in temperature. The mineral oils, or paraltins, do not. showthis decrease, but, on the other hand, increase in resistance withincrease of temperature. The mineral oils, however, are not suited forinsulation, as they do not dry but are liquid or become liquid withincreasing temperature. Furthermore, the solid p-araflin's are allbrittle and not sufiiciently tough for use. I have found in thecondensation product of a phenolic body and an aldehyde the valuableproperty of increasing in resistance with increase in temperature. Thiscondensation product is soluble in al cohol; has a fairly highdisruptive strength and is very easily applied. The condensationproduct, however, by itself is unsatisfactory as an insulating material,since it becomes brittle, especially when heated. In order to employthis material, therefore, I have found it necessary to combine it withother materials to give it flexibility and toughness. Inasmuch as themineral oils have the same properties as the condensation product asregards increasing in disruptive strength with increase of temperature,I employ mineral, or hydrocarbon, oil for mixing wit-h the same.Paraflin oil is well adapted for this purpose, but it has been foundthat it does not dissolve said condensation product and will not mixwith it. Furthermore, no solvent is known which will dissolve both thecondensation product and paraflin oil. a I have found that paraflin oiland the phenolic condensation product may both be brought in solution inthe same menstruum Specification of Letters Patent.

Application filed September 20, 1909.

Patented M ay 19, 1914-.

Serial No. 518,567.

in. the following manner; the condensation product dissolves in alcohol,while parallin oil dissolves in amylacetate. Alcohol and amylacetate mixreadily with each other. By using the combined solution, therefore, ofalcohol and amylacetate, these two materials, the phenolic condensationproduct and paratlin oil, mix and form a clear, transparent solution.Obviously it is important that the proper proportions be used. H. toomuch amylacetate and not enough alcohol is used, the condensationproduct is thrown down, and if too much alcohol and not enoughamylacetate is used, the parallin oil sepas rates from the solution. Asa suitable proportion, I find that a mixture of four parts bycvolume ofan alcoholic solution of condensation product with two parts of paraflinin seven parts of amylacetate is satisfactory.

This material when dried forms a rubbcw like mass of a character aboutmidway between soft rubber and .putty. I have found that this solutionof the condensation product and paratlin oil in alcohol and amylacetatecan be applied to fabrics or fibrous materials so as to produce aflexible insulating cloth. The compound remains tough and increases indisruptive strength with increase of temperature. The material iscapable of wide application in the electrical art.

\Vhile I have described my material as be ing produced in a definite wayand with specific materials, it should be understood that I do not limitmy invention thereto, since Various modifications thereof will suggestthemselves to those skilled in the art, without departing from thespirit of my invention, the scope of which is set forth in the annexedclaims.

IVhat I claim as new and desire to secure by Letters Patent of theUnited States, is

1. An insulating material composed of phenolic condensation product andhydrocarbon oil dissolved in a mixture of solvents for each of saidmaterials respectively, said solvents being miscible with each other.

2. An insulating material containing a phenolic condensation product andparailin oil dissolved in a mixture of alcohol and amylacetate.

3. An insulating material comprising a sheet of fibrous materialimpregnated with a mixture of a phenolic condensation product andhydrocarbon oil dissolved in alcohol and amylaeetate.

4-. A composition of matter comprising a a phenolic condensation productan oil and 10 resinous condensation product an Oil and a mixture ofsolvents for sold materials comsolvents for said respective substances,said prising ethyl. alcohol and. amylacetate,

solvents being miscible with each other. In Witness whereof I havehereunto set 5 A composition of matter comprising a my hand'this 18thday of September, 1909..

phenolic condensation product, a solvent JOSEPH L, R. HAYDEN.

therefor, an oil and a. solvent for said oil, Witnesses:

said solvents being miscible with each other: BENJAMIN B. HULL,

6. A composition of matter, comprising EMMA B. Coons.

